Transmission slipping, over heat, torque converter not engaging

[Garrett24]

My 2019 3500 when towing the trans temp gets between 195-210 and kicks into overdrive and won't lock torque converter. I did notice today that when it does this it throws a code for turbo charger communication error and when it switches from 1st to second its high rpm and snatches only when it gets over 200 and seems to be slipping 1st but only when it does this. Any help is greatly appreciated.

 

[Classic_Buzz]

When is the last time you've changed fluid? I have a feeling that might fix it. At least from what I see.

 

[Burla]

If you have that thermo bypass valve get that vegetation off yesterday, I do believe they use trans lines as "cooler" lines, it may be possible that cools turbo too. Find the bypass and get the bypass kit, get the temp down. Says 2018 they stopped bypass, dunno maybe 3500 still has it.

 

[Burla]

get one of these, it doesn't really matter the brand, they have no valve, that is the point. They just replace the thermo valve. Anything you buy off Amazon or eBay whatever will work fine. check reviews make sure not prone to leak.